Aeroplane.



R. P. CAMPBELL, JR.

AEROPLANE.

APPLICATION FILED MAY I0. 1913.

1,1 92,75 1 Patented July 25, 1916.

2 SHEETS-SHEET I.

R. P. CAMPBELL, JR.

AEROPLANE.

APPLICATION FILED MAY I0. 1913.

w m 3" m :7. P V.W 5 E E E m E 7 W u w @FEEE.

ROBERT P. CAMPBELL, JR., OF WATER/LOO, IOWA.

AnRorLANE.

Specification of Letters Patent.

Patented July 25, 1916.

Application filed May 10, 1913. Serial No. 766,684.

To all whom it may concern Be it known that I, ROBERT P. CAMP- nnLL, Jr., a citizen of the United States, and a resident of the city of lVaterloo, in the county of Blackhawk and State of Iowa, have invented certain new and useful Improvements in Aeroplanes; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the numbers of reference marked thereon, which form a part of this specifica tion.

In the rapid advance which has taken place in the knowledge of aerodynamics and in the art of aeroplane design, the progress of the successful machine has been marked by the successive and related steps in construction, each introducing an improvement contributing to the evolution of the modern machine, but as yet even this is highly imperfect.

In the earlier types of biplane construction the machines were provided with lifting surfaces in frontof, and at the rear of the main planes. With the further development of the art, the lifting surfaces in front of the main planes were dispensed with, a construction which was found to give much better satisfaction in actual op eration. In the most successful machines which are being built at the present time it has been found even more advantageous to dispense with the rear lifting surfaces, and substituting in their place merely the guiding mechanism for the machine. This practice of constructing machines with a non-lifting tail has become prevalent in monoplanes as well as biplane design. Of course, the variation in the disposition of the supporting surfaces has also changed the relative position of the center of gravity of the machine with reference to the sustaining forces with the idea of securing greater stability.

It is an object of this invention to still further plane by providing the same with a norincrease the stability of an aero-- provide an aeroplane equipped with normally acting lifting and depressing surfaces.

It is a further object of this invention to provide an aeroplane with a tail having an upwardly concaved surface acting to normally depress said tail.

It is also an object of this invention to provide a means for increasing the downwardly acting forces as well as the upwardly acting forces of an aeroplane with an increase in speed of the aeroplane.

It is also an object of this invention to provide an aeroplane with means for maintaining a predetermined constant speed in the operation thereof.

It is finally an object of this invention to provide an aeroplane construction in which the downwardly acting forces are balanced about and disposed on each side of the upwardly acting resultant force, as a fulcrum.

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

In the drawings: Figure 1 is a side elevation of a device embodying my invention. Fi g. 2 is a fragmentary top plan view thereof with parts removed. Fig. 3 is a diagrammatic view thereof showing the operation in an upwardly inclined position. Fig. 4 is a diagrammatic view thereof showing the operation in a downwardly inclined position.

011 the drawings: The reference numerals 1 and 2, denote respectively the upper and lower main planes of a modified type of fright biplane. Said planes are secured upon the framework 3, which is suitably mounted upon the usual skids l. Adjustably attached on the rear of said frame 3, and comprising the tail of the machine is the upwardly concaved depressing surface 5, which is suitably connected by means of cables 6, to the operating lever 7. Also mounted in said framework 3, and in advance of the surface 5, is the vertical rudder 8, connected by means of the cable 9, to a suitable operating lever 10. Mounted at the extreme forward end of the frame 3 is the engine 11, adapted to drive the propellers 12, by means of the chain 13.

Directly behind the engine 11, and c011- venient for the operations of the levers 7 and 10, is the seat for the operator, indicated as 14:, and shown in dotted lines. The usual ing force acting through the center of whereupon,

The operation is as follows: Assuming the aeroplane to be traveling at a constant speed in a horizontal line offlight, the various up ward and downwardly acting forces may be indicated by thearrows A, B, and C, of which the arrow A, indicates the resultant upwardly acting force on the main planes 1 and 2, B represents the downwardly actgravity of the machine, and C represents the downwardly acting force due to the in verted surface 5, mounted on the tail of the aeroplane. 'Said arrows are only used to conveniently represent the direction and application of the forces and are not meant to designate the relative magnitude of the same. It will be seen that whenthe machine is flying on an even keel that the downwardly acting forces B and C are evenly balanced about the upwardly acting force A, but should for any reason the speed of the aeroplane be abnormally increased, the force at C will be likewise increased, causing the tail of the machine to be depressed,

and such inclination of the machine, as shown in Fig. 3, will, due to the retardation of gravity, check the speed thereof. Should for any reason the speed of the machine be decreased while flying on an even keel, the force at C, which is a function of the speed, will likewise be decreased, and due to the unbalancing of the machine about the fulcrum point of application of the force A,

by means of the downwardly acting force B, the machine will be inclined downwardly, due to the acceleration of gravity, the speed will be greatly increased, until the forces once more balance each other to cause the machine to fly on an even keel.

As shown in the drawings, the plane 5 is adjustable, and the force acting thereon also being a function of the angle of flight of the plane, such force may be increased or decreased by the operator as desired.

As has been pointed out, the advancement Copies of this patent may be obtained for in aeroplane design is shown to have passed through two stages, namely first, machines provided with a lifting tail and secondly, machines provided with a non-lifting tail, such steps in the construction of the machine affording different relations to be effected between the supporting forces and the resultant force of gravity to obtain greater 7 stability. The applicant has gone a step, farther and not only constructed a machine with a non-lifting tail, but one provided with a normally depressing tail, such a feature enabling'the forces of gravity and the sustaining forces of the machine to be disposed in a new relation affording still greater stability and safety.

Obviously details of the construction and operation may vary through a wide degree.

I have merely shown and described a preferred form of my invention, and I do not purpose limiting the patent granted on this application otherwise than necessitated by I the prior art.

I claim as my invention:

An aeroplane comprising, in combination with vertically-spaced main planes, a framework rigidly connected to both to extend rearwardly therefrom medially, a vertically arranged ruddermounted in the rear part of said framework to swing laterally to either side, means for swinging said rudder, a horizontally arranged upwardly longitudinally troughed plane mounted transversely on said framework to the rear of said vertical rudder, and pivoted at its for ward edge to rock vertically, and means for rocking said troughed plane vertically, the latter being located and adapted to balance the other planes about the center of pressure ofthe'aeroplane. I

In testimony whereof I have hereunto subscribed my name in the presence of two subscribing witnesses.

lVitnesses I CHAS. W. KNooP, H. E. Ruse.

five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

